硒对锑胁迫下玉米生长、元素含量及锑积累的影响

发布时间：2018-06-01 18:07

本文选题：锑污染 + 硒　；参考：《山西农业大学》2015年硕士论文

【摘要】：采用盆栽试验研究土壤中锑(50、100、200mg/kg)亏染下,不同浓度硒(0、1、2、 5、10 mg/kg)对锑胁迫下玉米抗氧化酶活性、叶绿素、元素含量及锑积累的影响,为锑污染的合理防治提供科学依据。研究结果表明：(1)苗期玉米叶片中POD、CAT、SOD的活性均随着锑浓度的升高显著下降。当土壤中加入一定量的硒时,对三种酶的活性又产生显著性影响：低浓度的硒(2mg/kg)可以促进酶的活性,POD在硒浓度为1mg/kg时酶活性达到最佳,SOD和CAT在2mg/kg时酶活性取得最大值；而高浓度的硒(2mg/kg)则对三种酶活性产生了抑制作用,降低了酶的活性,对植物的保护能力也相应减弱。(2)丙二醛的含量可以用来衡量玉米叶片细胞的受损程度,而外源硒的加入可以明显减少MDA的含量,缓解锑的毒性,对细胞起到一定的保护作用。(3)与对照相比,土壤中施加的锑浓度越高,玉米叶片中叶绿素含量越低,而硒的加入显著降低了重金属锑对叶绿素的损害。低浓度硒(低于5mg/kg)因为与锑有较强的拮抗作用,有助于减轻锑对玉米叶片叶绿素的胁迫作用,使叶绿素含量增加;而高浓度硒(高于5mg/kg)却加重了锑对玉米的胁迫作用,抑制了叶绿素的生成。(4)通过对六种元素(Cu、Zn、Fe、Mn、Ca、Mg)含量的测定,发现不同浓度单一锑胁迫下的元素含量均明显低于对照(Ca除外,均高于对照),而添加硒可以使锑胁迫下玉米体内元素的含量高于单一锑处理,并且在硒浓度为2mg/kg时,达到最大值,但是施入高浓度的硒仍然会抑制元素的积累。(5)对于成熟期玉米鲜重和干重的研究,通过地上部分与地下部分的对比可以看出,单一胁迫锑浓度越高,对应的质量就越低,说明锑的毒性影响了玉米的生长和对水分的吸收。硒的加入降低了锑的毒性,使得玉米地上和地下部分生物量均有所增加且显著高于单一胁迫下对应的值,但是高浓度的硒仍对玉米生物量有影响。(6)通过对玉米根部、茎叶、籽粒积累锑含量的研究发现,施加锑的浓度越高,玉米各部位积累锑的量越大。硒对锑的拮抗作用表现为减少了玉米对锑的富集,首先低浓度的锑(50100mg/kg)随着外源硒浓度的增加,根和茎叶中锑的含量先降低后升高,并且在硒为2mg/kg时基本达到最小值,证明此浓度的硒是抑制根和茎叶富集锑的最佳浓度；对于高浓度锑(200mg/kg)处理下的玉米,低浓度的硒(2mg/kg)对根部积累锑表现出显著的抑制作用,但浓度过高则促进根吸收锑,茎叶中硒的添加虽然起到了一定的抑制作用,但高低处理间表现出的差异明显,相邻处理表现不明显；在玉米籽粒中,随着硒浓度的增加,三种锑浓度处理下的锑的含量基本呈现下降趋势,只有在高浓度锑(200mg/kg)和高浓度硒(10mg/kg)混合处理下的锑含量在下降后略有升高,但均比单一锑胁迫下锑的积累量要低。
[Abstract]:The effects of different concentrations of selenium (0,1,2, 5,10 mg/kg) on the activity of antioxidant enzymes, chlorophyll, the content of elements and the accumulation of antimony under antimony stress were studied under the effect of 50100200mg/kg deficiency in soil. The results showed that: (1) the activities of POD, CAT and SOD in Seedling Leaves of maize were all followed by the results of the study. The increase of the concentration of antimony decreased significantly. When a certain amount of selenium was added in the soil, the activity of the three enzymes had a significant effect. The low concentration of selenium (2mg/kg) could promote the activity of enzyme. The enzyme activity reached the best when the concentration of selenium was 1mg/kg, while the activity of SOD and CAT reached the maximum at 2mg/kg, while the high concentration of selenium (2mg/kg) was three. The activity of the enzyme was inhibited, the activity of the enzyme was reduced and the protective ability of the plant decreased accordingly. (2) the content of malondialdehyde can be used to measure the damage degree of the maize leaf cells, and the addition of exogenous selenium can obviously reduce the content of MDA, alleviate the toxicity of antimony, and protect the cells. (3) compared with the control, the soil has a certain protective effect. The higher the concentration of antimony applied in the soil, the lower the chlorophyll content in the maize leaves, and the addition of selenium significantly reduced the damage of the heavy metal antimony to the chlorophyll. Low concentration of selenium (lower than 5mg/kg) has a strong antagonism with antimony, which helps to reduce the coercion effect of antimony on the chlorophyll of maize and increase the content of chlorophyll; and high concentration of selenium (high concentration of selenium) 5mg/kg) aggravated the stress effect of antimony on Maize and inhibited the production of chlorophyll. (4) through the determination of six elements (Cu, Zn, Fe, Mn, Ca, Mg), it was found that the content of elements under the stress of single antimony under the different concentration was obviously lower than that of the control (except Ca, all higher than the control), and the addition of selenium could make the content of the elements in the maize under the stibium stress high. In a single antimony treatment and when the concentration of selenium is 2mg/kg, the maximum is reached, but the accumulation of high concentration of selenium still inhibits the accumulation of elements. (5) the study of fresh weight and dry weight of Maize in mature period can be seen through the comparison of the ground and underground parts, the higher the concentration of the single stress antimony, the lower the corresponding quality, indicating the toxicity of antimony. The growth of corn and the absorption of water were affected. The addition of selenium reduced the toxicity of antimony, which made the biomass of both the ground and underground parts of corn increased and significantly higher than the corresponding values under single stress, but the high concentration of selenium still had an effect on the biomass of maize. (6) the accumulation of antimony content in the Rhizopus, stem and leaf and grain of the corn was studied. At present, the higher the concentration of antimony, the greater the accumulation of antimony in each part of the corn. The antagonism of selenium to antimony shows that it reduces the enrichment of antimony in maize. First, the content of antimony in the low concentration of antimony (50100mg/kg) decreases with the increase of the concentration of exogenous selenium, and the content of antimony in the root and stem leaves first decreases and then increases, and the minimum value is basically reached when selenium is 2mg/kg. Selenium was the best concentration to inhibit the accumulation of antimony in the roots and stems; for the Maize Treated with high concentration of antimony (200mg/kg), the low concentration of selenium (2mg/kg) showed significant inhibitory effect on the accumulation of antimony at the root, but the high concentration promoted the absorption of antimony in the root. The selenium addition in the stems and leaves played a certain inhibitory effect, but the high and low treatment was shown between the high and low treatments. With the increase of selenium concentration, the content of antimony in the three kinds of antimony concentration decreased with the increase of selenium concentration. Only the content of antimony in the mixture of high concentration of antimony (200mg/kg) and high concentration of selenium (10mg/kg) decreased slightly, but the accumulation of antimony under the single stibium stress was higher than that under the single antimony stress. The amount of tired should be low.
【学位授予单位】：山西农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X173;S513

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